Windshield wiper



July 25, 1950 H. E. ROSE 2,516,594

WINDSHIELD WIPER Filed April 7, 1944 4 Sheets-Sheet 1 MAG-Mm)? J/owA 20 5. E054 5W Quay fir TO QA/EKS.

July 25, 1950 H. E. ROSE 2,516,594

WINDSHIELD WIPER Filed April 7, 1944 4 Shee'ESSheet 5 f/awA ED 5. R055 aw y d July 25, 1950 H. E. ROSE 2,516,594

WINDSHIELD WIPER Filed April 7, 1944 4 Sheets-Sheet 4 Patented July 25 1956 WINDSHIELD WIPER Howard E. Rose, Peninsula. Ohio, .assign'or, by-

mesne assignments, to Kearfott Company, Inc;, New York, N. Y., a corporation ofNew York Application April 7, 1944, Serial No. 529,964

20 Claims;

The present invention relates to a windshield. wiper,.and-more particularly to one that is fluid.

operated. A-particular object of the invention isto provide improvements on a wiper mechanism" such as is described in co-pending application, SeriaLNo. 467,359, filed November 30, 1942,- now. Patent No. 2,e46,6ll, August 10, 1948.

Among these improvements are the provision. of a-simplified windshield unit wherein a Valvev construction. is made of parts easier to fabricate, and which give superior operation. More particularly, it is an object to provide a windshield unit having valves that attain the objects of slide valves but without the disadvantage thereof.

A=further object of the invention is to provide aspeed. control valve having means readily adaptable to varying supply pressures.

Further objects are to provide a compact, easily made, easily repairable reversing Valve mechanism that is pressure responsive to reverse- Whenthe fluid pressure in either of its linesattains a predetermined value.

A-further object isto provide a Valve mechanism having a locking valve that is automatically operableto retain the windshield wiper mechanisms immovable when the main control valveis closed. to render the mechanism inoperative.

In the drawings:

Fig. 1 (sheet 1) is. a view of the windshield wiper: as. installed, certain-parts being in section;

Fig. 2 is a side elevationof the motive unit. or control valve mechanism shown from the right side. thereof on the; line 22.oi Fig. 1;

Fig. .3;is an elevation of the motive unit taken from the left side of. Fig. 1 on the line 3-3;

Fig. 4 is an'end elevation of the motive means taken'at the top thereof in Fig. 1 on the line Fig. 5 (sheet 2) is a vertical section through the motive unit taken on the line 5-5 of Fig. 1;

Fig. 6. is a vertical. section through the motive unit taken on the. line 66 of Fig. 1;

Fig. 7 isa. vertical transverse section through the motive unittaken on the line l'! of Figs.

Fig. 131 isa horizontal section on the line I3.-l3 ofi'Fig. 6;

Fig .,.1.l is. a horizontal section.on the. line l-ieeiflgofjjFig. 6;

Fig. 15*(sheet 4) is a transverse'view, throughthe speed control valve;

Fig- 16is a transverse section through eachv of..,the window controlunits taken on the'lines I B. l.6.of Fig. 1;

Fig. 17 is an axial'section through. one ofzthe Window control units in a first operating position ;v and?.

Fig... 18. is an. axial section through the otherwindow control unit.

In general, the mechanism includes one or more. windshield wiping, devices such as 29" and 2], .operated'respectively by Window control units Hand 23; The window control units, in turn, are operated by a motive unit or valve control Mthat isconnected to the window units 22' and 2.3.103 tubes 26 and 2T, respectively, the two window units. being connected together through a tube,28.. Themotive control 2 3 receives pressure fluidfroma line iill'that is controlled by a speed control. 3.1. Themotive control 24 exhausts into alowpressureline 32.

The overall functioning involves the admissionthroughthe speed control of hydraulic fluid at a pressure determined by the settingv of the speed .control ,3] inthe line 30. This high pressure fluid is automatically alternately introduced through the. motive unit 24 into the tubes 26 and".21. When one of the tubes 26 and 21 is receiving high pressure, the other is connected through the motive unit 24 to the low pressure return.32. The high pressure liquid in one of thelines 26 and'Z! acts against a piston mechanism within the respective windshield unit to which. the particular line is connected. This piston mechanism causes operation of its wiper 20. or 2!, as the case may be, and, in the same operation, eiTects high pressure in fluid within -theconnecting line 28', so that the piston mechanism of the other windshield unitmay be' operated.

The two piston mechanisms contain pressure resisting means so that when, and only when, both wipers 20"and 2! are stopped, the high pressure in the system to the right of the motive unit 24' willattain a certain high value. When this value is reached; the motive unit 24 operates to reverse the connections between the inlet 38 and the exhaust 32 on the one hand, and the lines 26. and2'l on the other; so that theoppositeof the two lines wand 21 are connected to pressure and. exhaust, respectively. Thereupon, the wipers. 2i) and 21 are moved in the other directioniuntil both are stopped and the critical pressure condition is again obtained.

Fron'rthe foregoing, it may be understood that themotive unit Z4-"comprises a valve mechanism 3 including a valve that directly determines the connections of the lines 26 and 21 with the pressure and exhaust lines 39 and 32, and includes pressure responsive means to effect the positioning of the said valve. This motive unit will now be described.

This valve includes a body 35, into one face 36 of which the inlet 38 and the exhaust 32 are connected. At the end of the opposite face 8'! of the valve body 35 the wiper connections 28 and 2'! are introduced.

The pressure line 38 connects into a port 40 (Figs. 8, 13). The line 40 connects with a vertical port M (Fig. 8) leading to valve chambers 32 and 43 receiving the valves B and C, respectively. The port 48 also connects with a valve chamber 4 2 of the valve A by an angular port 45 bored down from one of the angular upper faces of the valve body 85 and plugged at 46.

The port 48 is also connected with a port 41 drilled in from a face d8 of the valve and plugged at 49. This port 41 (Fig. 11) is connected by an angular port 50 with one end of the chamber of the valve L.

From the foregoing, it may be seen that pressure is constantly admitted to the three valves A, B and C at the middle of their respective valve valve chambers. A port Q82 leads to the valve A, a port I83 leads to thevalve B, and a port I84 leads to the valve C.

Referring to Fig. 9, it will be seen that there is a port I88 connected from the exhaust port Iill to the other end of the valve A, a port I01 connected to the other end of the valve B, and a port I08 connected to the other end of the valve C, and a port 189 connected into the spring chamber 86 of the valve L. All of the ports IIlfl through I89 are constantly connected to the exhaust line 32 through the ports I08 and II.

The two wiper lines 28 and 2'! are connected directly to the chamber 5| of the valve L (Fig. 14). The line 26 is connected to a port H2, leading to a cross port I18, connected to a port H4 that, in the position shown, registers with a sealing portion 92 of the locking valve L. The port H4 is continued on the other side of the sealing portion 92 as a port H5 leading to the chamber 43 of the valve C and, as shown, to the space 85 thereof. As shown in Fig. 6, the valve chamber Si is also connected by a port II'I with the pressure chamber 62 of the valve A.

chambers, and is also connected to the end of The valve A slides within the chamber apart by a coil spring 86 to the maximum distance permitted by opposed washer engaging shoulders, one at the base of the extension 63, and the other determined by a nut 81 threaded adjustably onto the extension. A cap 68 is screwed into the valve body. This cap 68 actually contains the pressure chamber 82.

It will be seen that the valve B, operating in the valve chamber 42, is a slide valve having sealing portions Ti), H and i2. The portion H is provided with a balancing groove. Between the portions all and l! is a porting space i3. Between the portions H and i2 is a porting space E5. The ends of the valve chamber 42, which constitute pressure chambers for the valve, are designated at I6 and '71.

It will be seen further that the valve C, operating within the valve chamber 43, has sealing portions 88, 8| and 82, which, as shown, provide porting spaces 83 and S5. The sealing portion BI has a balancing groove therearound. The two operating pressure chambers are designated 86, 81.

The valve L, operating within the valve chamber 5I, includes sealing portions 90, BI and 92, which provide porting spaces 93 and 94, as shown. The operating pressure chamber is designated at 95, and a spring chamber 96 is shown at the opposite end. The valve body on this valve L has an extension 9! within the chamber 98 receiving a compression coil spring 88, normally urging the valve to the left in the drawing.

The exhaust line 32 is connected to a port I00 (Fig. 13), and thence to a cross port IIlI bored in from the face 48 of the valve. The port II is connected by angularly disposed ports with three of the valves, as shown in Fig. 7, through ports leading to the leftward ends of each of the The line 21 is connected into a line I20 leading to the chamber SI of the valve L, and shown as registering with the sealing portion 9| thereof, beyond which it continues as a port I2I opening into the chamber 43 of the valve C, where, in the position shown, it registers with the porting space 83 thereof. Again referring to Fig. 6, it will be seen that the port I22 connects the valve chamber 55 with the pressure chamber 8| at the other end of the valve A. The ports H5 and III open into the chamber SI of the valve L at the same distance along the axis thereof. The ports IZI and 22 do likewise.

The valve A controls the pressure conditions in the pressure chambers of the valve B. Referring to Fig. 12, it will be seen that the chamber 44 is connected by ports 125 and I28 to the pressure chamber #8 of the valve B. It is also connected by ports [2'1 and I28 to the pressure chamber TI at the other end of this valve B. When the valve A is in the neutral position shown, the ports I25 and I27 are closed by the sealing portions 55 and 56 of the valve A.

The valve B, in turn, controls the pressure conditions in the pressure chambers for operating the valve C. In Fig. 5, it will be seen that constricted ports I38 and I3I lead from the valve chamber 42 of the valve B respectively to the chambers 86 and 81 of the valve C.

The wiper units shown in Figs. 16-18 are identical. Each includes a housing or cylinder I40 in which a piston I4I reciprocates. The cylinder I48 has a cap I42 at one end, and a cap I43 at the other. Each cap holds a check valve and retainer 44 in position. The retainers are identical, being annular in shape and having grooves I 4'! to receive ball check valves I45 controlling small ports I48. The grooves in which the balls are disposed are continued to the end of the flange. It will be seen that the retainers are shaped so that the balls are held in the grooves by the end of the cylinder I48. The length of each retainer M4 determines the limit of the piston stroke in its direction. Use of retainers of difierent lengths easily varies the length of the strokes.

The piston Mi. has a central bore therethrough, the center part of which receives a tubular sleeve I48. The sleeve has holes I49 and I 58 through its walls for purposesv to be described. The opposite ends of this sleeve I48 are adapted P etra; 5942 tblbe closed: by valvesllfitandkl 512i 'rhevaive Ifi'I' is :urged-into sealing positionhy. acoilispring I53. and a similar. coil spring; L514; acts. against: the:- valve" I52. A..cap I55, openlat I56, contains'the springi53land a:simi1ar cap1I'5-1; openat. IB:,.con;- tains the other spring I541 The'cap I42 of the wiper. unit: 2 22' is connected; to the line-26 and the cap i 43 isiconnectedtothe line 28; which leads to theother wipenunit' 23;. identical with the; first one. The. parts of; the. second element 23 are designated by the" same. reference numerals withprimes? annexed thereto; Consequently, the. line 28- will connect into: the. cap I43 and the cap I 42 will connecti'to' the line 2-7.

The-pistons WI and: MI." have rackportions thereon that-operate, respectively, gears lttiand" ltd connected to one of. the'wiper elements here. Shown at 2-5.

The speed control valve 3:I is-shownin detail in Fig; It includes an inlet port I? I connected to the" pressure supply: and an outlet I12 connected to the line 361. The' inlet threads are adapted toreceive -acollar I la having aport I 14 therethrough. The collar has-a- Keri to receive ascrew-driverfor its insertion andrem'ovall By this means-a collar may be installed thathasaport I 74- of a proper 'size to givethe desired pressure conditions.

The inlet l ll connects with the'port Ila-leading to a valve seat member IN. The seatimem-- her titreceivesa valve plug Iii 3 formed on a valve stem 18 with a notched" guiding extension H 9 slidably. in the seat member I 16. The notch on the extension ITS-provides increasing flow as the valve stem islifted. The valve stem. has spaced flanges Illfl'andf I8"! slidable within. the cap- H32 andreceiving a rubber ringseal N33. The stem is-tliread'ed through the cap I8?) and has a handle I 84' for operating the same.

Operation Torstartxthe' wipers; the. valve I3. is1openedi byturningsits handle 48:4 to admit fluid under-pres.- sure tov the: line at. This fluid under pressure then enters the valve 35, and, referring to.Fig;.10, is imme'diatel distributed to' the portingspace. 59 of the valve A. (assuming. allof the. valves to: he in the position shown), to the porting'space: I5; of the valve B, to the. porting space; 8.5.: of. the valve'C; and to the chamber 9 50f the valve L. Tihe'locking valve Lin the position.oflli'ig-.. 105 has its sealing portions 9! and'tzidisposed across the outlet ports 26 and 211 leading torthe. wipers, so that they arecut ofi; However, when the press sure fluid is admitted by the. speed control valve 31, it overcomes the force of thespring' 98,.acting onsthe valve: L, and that valve will be moved over so that it disposes the porting space 93; to connect. the line H with the port". IZI, and dis.- posesthespace 94 to.c0nnectthe line 28 withthe port H5. Thereupon pressure will flow from the line 30 through the lines 49 and 4t to the space HBtEofthevalveC, through the line I5,- andto the line 26. At: the same time, the pressure flui'd'is adinittedfromthe port II5 through the linev Il-l to; the-.chamberfi I of the. Valve A.

With; the. locking; valve L. moved as heretofore indicated, the other line 2'! at the other end of thewiper unitswill.beincommunication withthe line. I211 leading'to the space 83 of. the valve G, which at this time also registers with. the port IM- leading' to the exhaust line 32. Whereupon the otherend of the wiper units is exhausted to low pressure, At the sametime', the-line I22i eonnecteditos:exhaust andgthislrelievesxtheehahia' end of. thesleeve I418, it. Will-Y displace the: same.

toithe. rightrto move it: away I from. the; valve il5:I.-, the: said: valve having: radial extensions prevent.- i ng its'followingLthesleeve. This opening off-the valvezI5 lLadinitsrpressure fluid against thezendroi; the valve I 52-; Pressure'acting. against: the: end of thesleeve I148; andzagainstthe' inner: partot the valve: I52; will move both. to thelrightiagainstz thespring I541 When a predetermined pressure exists, the displacement will have been. siuch=as to expose the hole.- II59 to. the. right: side of the; piston,- whereupon the liquid will; flow into; the line 28.

The resistance offered by the. spring I54 greater thanthe normal resistance: to displace:- ment" of" the entirepiston MI and associated windshield wiping elements, so that this prose surefluid will displace the piston to the right;v When the piston is stopped: by the: en.- gagement of" its right. end against the retainer I'MI'at the rig-lit, the pressure within the flange; to tl-ieleftofthe piston maybe built-up further. until it displaces the sleeve M8 and; opens th'e hole- I5IJ; Thereuponit will" flow through. the line 2 8 filling the same, and; will enter through the cap I43 intethe cylinder I40, and act against the right end of thepiston I4I', SOi that it-tends to displace this piston to the left in Fig. 18. The piston will yield to the left, as the-re:- sistance of the wiping mechanism is less than the resistance offered by the spring I533 until the piston stops in the left end of the cylinder; Thereupon, the pressure in the line 28, the line 26, andthecylinder I40 willtend to-increase to displace the sleeve I48 and to overcome the spring I53 It'willbe observed that atlthis point the "springs I54 and I53" are in series.- Consequently, before both may be displaced the fluid pressure must attain a highvalue above that requiredto' discplace a single-one of the valves. Before'thislast maximumpressure is attained, however,- the cons trol mechanism 35 will be operated as follows It has been noted previously that the. pressure in the=line 26 is acting within the chamben. E2 of the relief valve- A. The locking valve. L. is opened when the speed controlvalve. 3i is. open. The valve A resists displacement in. accordance with the force exerted by the spring: 66?. This springis designed to: exert a force that is less than the force. exertedby the pressure fiuidupon the" Valve A, when all of the window element springs are series, but: greaterv than the. fluid pressure when-one less than all of the said springs are'in series; Toillustrate, the normal maximum operating pressure to move the wiper units, is 400 p. s: i. The valve A is set to operate at 450 p. s. 1. Where two windshield units are used; eachvalve may have an effective resistance of 2.50 p. s. i.

Consequently, the valve A is not moved when the spring. [54 yields in the Window element: 22'. But,.when the force of the sprin I53 in the window element 23. is: added as a resistance, the valveAis. shifted before; the spring I53! yields.

The: foregoing action will, cause the: valve. A

to move from its neutral position toward the left in Fig. 10. When this occurs, the pressure port 45 is connected to the ports I25 and I26 through the space 59, thus admitting pressure fluid to the chamber "I6 of the valve B to move the same. to the right. At the same time, the displacement of the valve A connects the ports I21, I28, leading from the other actuating chamber I of the valve B to the exhaust line I 06 through the porting space 66 of the valve A. This permits the fluid within the chamber TI to escape to the exhaust line 32, so that the high pressure admitted to the opposite chamber I6 of the valve B may efiect displacement of this valve to the right.

When the valve B moves to the right in Fig. 10, the pressure line 40 is changed from the porting space I5 to the porting space I3, as the sealing portion II moves from one side of the center to the other. This action also connects the pressure line to the restricted port I30 leading to the chamber 86 at the left of the valve 0. It also connects the other Operating chamber 81 of the valve C through the line I3I to the space I5 of the valve B to the exhaust line I01. In the meanwhile, the space III of the valve B seals the exhaust ports I03 and I04 from the space 76. v

The foregoing action of admitting pressure fluid to the chamber 86, and exhausting the chamber 81 of the valve C, causes the same to be moved to the right. This action shifts the pressure application from the line 26 to the line 21; In order to do this, the pressure lines 40, II are shifted by displacement of the portion 8| of the valve C from the space 85 of that valve to the space 83. Thi introduces pressure fiuid from the line 40, II through the space 83 to the line I2l, whence it passes through the open locking valve to the line 21.

At the same time, the space 85 is displaced to connect the port I I5 with the exhaust port IE8, so that the other line 26 is connected to exhaust.

It will be seen that the directional valve C is the one that finally causes the reversal of the pressure conditions of the wiper units. Since the ports I30 and I3I are restricted, the valve C will not be displaced completely until the valve B has been completely displaced. This action elimihates the necessity of a snap-action means on the wiper unit, because it insures that the pressure conditions, acting to displace the valve A through the ports II! or I22, will always remain without change until the valve B has completely moved. After the valve B has taken its new position fully, it controls the porting to the valve C regardless of whether the valve A returns to neutral position or not. a

As soon as the pressure in the line 26 is re lieved into exhaust, the pressure within the line In is relieved and the spring 66 forthwith returns the valve A to its neutral-position; This displaces the spaces 55 and 55 across the ports I25 and I21, and hydraulically locks the valve B in position. The valve C is, as a consequence, held in its position by the fixed pressure condition set by the valve B.

With the pressure conditions thus reversed, the line 21 will become the high pressure line, the line 26 the low pressure line, and the pressures within the two windshield units 22 and. 23 Will be directly reversed from those previously described. The high pressure introduced in the line 21 will act against the left of the piston, MI. until the same has moved to its limit, whereupon the sleeve I50 will be displaced and will o en;

.113 will he recognized that at thi im the 8 space between the two istons MI and IE1 will be filled with liquid from the previous initial operation. Consequently, the displacement of the piston I4I' to the right will, through the transmission of force by the entrapped liquid, correspondingly displace the piston I4I to the left. Both wiper elements will, therefore, move simultaneously. Should there be any escape of the entrapped liquid, the unit I II' will reach the limit of its stroke before the piston MI reaches its limit. Thereupon the valve I50 will open and enough liquid will flow past it to cause displacement of the piston I4! until it is stopped, whereupon both valve springs I54 and I53 will be put in series, causing a greater force resistance than that exerted by the spring 66 upon the valve A. The valve A will then move from its neutral position to the right, reversing in succession the valves B and C, and finally reversing the pressure conditions in the lines 21 and 26.

When the speed control valve 3| is cut oii at any time, and the high pressure reduces, the locking valve L will close, as its pressure chamber is relieved by leakage around the several slide valves.

It will be observed that the istons on the windshield units, as they approach the ends of their strokes, slip into the flanges of the retainers I44. The liquid trapped in the grooves It? must bleed out past the slightly tapered end of the pistons MI and MI", producing a cushioned stop for the pistons.

Should one of the wipers be stopped short of the end of its stroke, the effect will merely be that the other wiper is caused to go completely to the end of its stroke, and then upon return the two will act together. This comes about because the reversing pressure conditions are not met until both wipers are stopped at the same time. It is only when both are stopped, that both springs are put in series. Prior to that time, if one stops, its spring will yield and bypass oil either to cause operation of the other to the end of its stroke, or to permit operation of the other to the end of its stroke, depending upon whether the lead wiper or the trailing wiper has been blocked.

Furthermore, the wipers will always synchronize immediately whenever they have gone out of synchronism. This comes about because in either direction of travel they always move as far as permitted until both are stopped, which normally is when both pistons have struck their respective retainer members.

It will be seen that the locking valve L moves to locking position whenever the main fluid line 30 is cut off. Thus, if the speed control valve BI is closed completely, pressure in the line 30 drops off and immediately allows the locking valve to shift to the position shown. Thereupon the fluid is not relieved from the windshield units and they are locked hydraulically against movement in response to wind pressure and the like.

What is claimed is:

1. In a mechanism of the kind described, a high pressure line, a low pressure line, a first work line and a'second work line, a, control mechanism for selectively connecting the high pressure line to the first work line and the low pressure line to the second work line and vice versa, said control mechanism including valve means, operated in response to predetermined pressure in the work line receiving high pressure, to shift the-connection to admit high pressure to the other work line, valving means operated only upon the existenee, of high pressure in the high pressure line lil,

to provide rconnectionrbetweenzthe. work-lines and. pressureline is above apredetermined minimum a pressurelinersaid last-named valvemeans oomprising/av pressure -responsive valve. device...c.onv nectedl-to receive pressure. from Qthe .rhigh pr'ese l,

sure. line independently Lof said shiftable.v valvev closing-v both work lines. when it is not displaced to open position".

fluid. pressure windshield wiper unit, having a member moved back and forth in response to high pressurenon .opposite sides .thereof ,1 a high pressure line connection, .a 10w pressure line con? nection, a firstwork-lineto conduct fluilitoone.

side of the member a secondwlorlr line-fconnected to theotherflsidethereoi, control mechanism in-- terposed between the high andulow pressure connections and thekvvorkliiies to connect the, high I pressure Aline connection to, the first work, line l and the low pressureline connection to the. sec,

ond workilineiand viceversa, said, controljm'ech, anism including reversing. valveinieans responsive to the. ipressurehin the .high pressure [work line to shift. thehonnectiohsto connect the; high pres-.

surelineconnection to. the second work line, and, a pressurerioperatedilocking Lvalve .means in the 1 work 1ines, said; locking .Mvalve. having opposite, actuatingschambersinterconnectediwith the high and low-pressurelin connections, independently of said reversing valvelmeans wheiieby whenever the. pressure edifierencelbetween said high 7 and low pressuremonnections. to the "reversing valve exceedsa. predetermined value. said locking valve Willopen saidwork lines to the; reversing valve means,andwhen.saidpiiessuredifference descends below. saidevaluelesaid. locking valve will close to lock the fiuidin .thewindshield Wiper unit and holdlthe. unit againstmovement.

3. In a mechanism of the kind described, aplu; ralityof .windshield wiping .units each comprisinga movablenmember,adapted,to be moved oppositelyin 'responseto application of fluid pressure-to opposite;sides'.thereof, a line. connecting .15

one lsidelof each. movable; member with oneside of the movable rmemberiof the nextv unit, "a high pressure.linelleadinglinto the first unit-a low press surelin'e leading from the last unit, pressure "responsivebyepass meansto admit pressure gfiuid around each rmovable member upon thej-attain-- ment of .a predetermined resistance to move mentsther'eof sothat. when pressurefluid'i's introduced through the high pressure .line' it may act against all of 'the by-pass means in series, a

reversing control mechanismadapted to connect a high pressure source. with the'high'press-nre line and a low pressure exhaust-with'thelow' pressure line and vice versaysaid control'mech-=- anism including a valve m e'ans' operable in response' to a, high'pressure in the high pressure line greater than all but -one of--the"by passing re sistances but-less--'than=all or them; said=.valve: means being adapted when moved "to effect reversal of the pressure connections' to the high and low pressure lines, l a pressurei-nperated locle ing valve interposed betweerrrrthet'reversingtvalvd' and-the windshield units,-=.means urgingztherlock-s ing'valve" into 'closedrpositionvtowblochcfiovvl ofvalue, h

4. In amechanism of the kind described, a controlgvalve including a valve housing for slide 5 valves therein, a high pressure inlet into the means, .ior displacementmto open, position; ,and means normallylurging. theLvalvel device to closed, position, the valves device having valve elements housing, a low pressure outlet, from the housing, anda pair of working linesleading from the housing, one of said valves comprising a locking valve, means, normallyurging the locking valve 10 to a cut-off positionwherein it blocks connection 2. In a, mechanism of thejkind' described, a

of the two working lines from the other valves, andmeans connecting the high pressure inlet to theother valves and to the locking valve at all times, said connection to the'locking valve being suchas to, cause said high pressure to move the same .to open position against said urging means 5. A hydraulically "operated windshield wiper unit including a cylinder means, a movable device in theLfiYlinder means adapted to receive fluid pressureson opposite sides thereof for movement back and'forth, by-pass means including a conduit to connect one side of the movable means with the other side thereof and pressure-responsive valve means controlling said conduit, said 5 va1ve means including a hollow slidabledevice in said conduit, two oppositely spring pressed valves, one urged against each end of said hollow device" to close the opening therethroughysaid slidab1e-: device being exposed at its 'ends to the pressure '3 conditionson opposite sidesnf the movableidevice,

and movable under "influence-of predetermined excess of pressure at one: of its ends over that at its other-mend, means limiting-the movement of each of the valve-means td-permit;the-hollow=- deViGSwtO move :away vfromweach -ofthe valve mea-ns-" un'der said pressure conditions, so that; fluid nnder pressure --may= flow into "the hollow device and-act againstlthe other-valve means at the-'othemend thereof, and;displa.oe.,thehollow,

4 device:and thesaidiother; valve means-,and means to effects communication,,.-around,rthe ,movablet deviceaftenpredetermined movement ,of. the 1 01; lowi-devicew 6- A hy raulically .opera ed .lw ndshield w nes 1 unit including,acviinderimean a. movable. evice,v

in the cylinder im ansuadant d. (t receivev id,

pressures on opposite. sidesthereoi ,torm r back .androrth, biz-pass meansi ludmea duit.,to connect one side of the movable means with the, other sidethereof and pressure-respon- 5 sive .valve,,means controlling said conduit, said valve means including a hollovv slidable device in said conduit, two oppositely spring-pressed valves, one urged against each end of said hollow device to close the opening therethrough, said slidable 1 device being exposed at itsendstothe pressure conditions on opposite sides of the movable device, and movable under influence of predetermined excess of pressureat one-of its ends over-that at its other end; means limiting'the movement of 59 each of the valve means? to permit-the'hollow deviceto move away from each .of't-hevalve means under said pressure conditions'so that fluid under; pressure may flow into the-hollow: device andract against the other valve means at the other end thereof; and; displace the hollow device-andthe said otherrvalvemean-s,;-and;means to effect com-- munication r around: the movable device "after predetermined -movementof 'the hollowdevice said lastenamed means, comprising port; means throughthe Wall of the hollow: device adaptedto be :exposed .upondisplacement tof .the same as aforesaid.

'7. .A hydraulicallyroperated mechanism inclilldr:l a-a hydraulic line. andga valve, device therein,

s d: ev vinsua lconstrictedrp ssase t erei enlarged at its opposite ends, a hollow slide having port means therein and reciprocable in the constricted passage, and being substantially coextensive therewith, a pair of poppet valves resiliently urged oppositely against the ends of the slide to close the port means thereof, said poppet valves being movable toward and away from the respective ends of the hollow slide, means limiting movements of the poppet valves in their directions toward the slide, said valves being shaped so that, when closed against the ends of the hollow device, they expose the said ends, whereby when fluid pressure is applied to either of said valves and the corresponding one of said ends the hollow device may be forced away from the valve, and conduit means opened upon predetermined movement of the hollow device.

8. A valve means for use with a windshield wiper mechanism comprising a hydraulically operated windshield wiper unit, a hydraulic pressure line adapted to be connected to the unit to introduce operating fluid thereto, the valve means being adapted to be interposed in said line to control the pressure in said line to control the speed of the windshield wiper unit, said valve means having a housing containing a valve seat therein, a valve cooperable with the seat, and a threaded port leading from the seat through the casing wall, said port being adapted to be connected with said line, and a removable orifice member comprising a threaded plug with a hole therethrough, said plug being insertable into the threaded port prior to connection with the line.

9. In a mechanism of the kind described, a pressure control having a fluid pressure inlet and an outlet, a pair of fluid-pressure lines, and pressure-responsive means selectively to connect one of said lines to the inlet and the other to the outlet and vice versa, said means comprising a directional valve adapted to be moved to effect connection of the first line to the inlet and the second to the outlet, and vice versa. said directional valve being adapted to be moved by application of pressure oppositely thereon, and an oppositely movable, pressure-operated relief valve movable for admitting pressure selectively in one of two lines in accordance with the position of the relief valve, said relief valve being connected to receive the high pressure as it is applied to the fluid-pressure lines. for displacement thereof in one direction or the otherin accordance with pressure conditions of said lines, force means resisting displacement of the relief valve, normally urging it in both directions toward neutral position and permitting displacement of the relief valve only when the pressure of the respective fluid-pressure line attains a predetermined value, and means responsive to the pressures in said two relief valve lines to effect shifting of the directional valve to its other position reversing pressure connections of said lines.

10. In an apparatus of the kind described, a pressure control having a fluid-pressure inlet and an exhaust, a pair of fluid-pressure lines, and pressure-responsive means selectively to connect one of said lines to the inlet and the other to the outlet and vice versa, said means comprising a valve adapted to be moved to efiect connection of the first line to the inlet and the second to the outlet, and vice versa, means controlling the position of said valve comprising mechanism movable in opposite directions from a neutral position in response to pressure changes oppositely acting thereon, yieldable means urging the same into displacement until the pressure in one of the lines receiving fluid under pressure attains a predetermined value, and means operated to reverse the valve upon displacement of the mechanism.

11. In an apparatus of the kind described, a pressure control having a fluid-pressure inlet and an exhaust, a pair of fluid-pressure lines, and pressure-responsive means selectively to connect one of said lines to the inlet and the other to the outlet and vice versa, said means comprising a valve adapted to be moved to effect connection of the first line to the inlet and the second to the outlet, and vice versa, means controlling the position of said valve comprising mechanism movable in opposite directions from a neutral position in response to pressure changes oppositely acting thereon, yieldable means urging the same into neutral position, ports connecting opposite sides of the mechanism with the respective lines, whereby said mechanism responds to pressure conditions thereof, said yieldable means resisting displacement until the pressure in one of the lines receiving fluid under pressure attains a predetermined value, and means operated to reverse the valve upon displacement of the mechanism, said last-named means comprising a second valve operable into two positions, in one of which it connects one side of the first valve to pressure and the other side to exhaust, and vice versa in the second position, means operating the second valve to one position or the other in response to the operation of the mechanism from its neutral position one way or the other, and means insuring complete operation of the second valve by the time the first valve has shifted to efiectively reduce the pressure acting to shift the mechanism.

12. In a mechanism of the kind described, a pressure control having a fluid pressure inlet and an exhaust, a pair of fluid-pressure lines, and means selectively to connect one line to the inlet and the other to exhaust, and vice versa, said means comprising a first valve displaceable to efiect said connections selectively, and opposite pressure means adapted selectively for connection to fluid pressure or exhaust for displacement of said first valve, a second valve controlling said opposite pressure means of the first valve, the second valve being displaceable to connect selectively one side of said means to pressure and the other to exhaust, and vice versa, means restricting the fluid flow around said second valve to said opposite pressure means of the first valve to delay action of the latter, opposite fluid pressure means adapted selectively for connection to fluid pressure or exhaust for displacement of the second valve, a third valve having opposite pressureresponsive operating means connected to the fluid-pressure lines and under control of the first valve, yieldable means urging the third valve into neutral position, said third valve being adapted to be displaced by admission of fluid under pressure to its opposite pressure means and building up of said pressure to predetermined values exceeding the resistance of said yielding means, said third valve, upon such displacement, being adapted to connect the pressure means of the second valve to pressure and exhaust to reverse the second valve, said connection being free to cause rapid movement of the second valve, wherepilot valve by the time the directional valv has egeregzsiat upon the secondvalve more slowly effects-reversal of the first, and the last-named valve reverses pressure conditions in the lines. I

13. 'In a mechanism of'th'ekind described, a

pressure control having a fiuid -pressureinlet and an outlet, a pair of fluid-pressure lines, and pressure-responsive means selectively to connect one of said lines to the inlet and the other to the outlet and vice versa, said means comprising a directional valve adapted to be moved to effect connection of the first line to the inlet andthe second to the outlet, and vice versafsaid directionalvalve being adapted to be'm'oved by application of pressure oppositely thereon, and relief valve means movablefor admittingpressure'selec tively in one of two lines in accordance with'the position of therelief Valve means, said relief valve means being connected to receive the high. pressure as it is appliedto the fluid-pressure lines, for

displacement thereof in accordance with pressure conditions of said lines, force means resisting displacement of the relief valve means, and permitting displacement of the relief valv .means only when the pressure of the respective fluidpressure lineattainsapredetermined value, and

means responsive to the pressuresin said two relief valve lines to effect shifting of the directional valve to itsother position. reversing pressure connections of said lines, said last means including .a pilot valve interposed between the relief valve means and the directional valve, said pilot valve being movable from a position to admit high pressure to oneside of thedirectional valve to a position to tadmitihighipressureto the opposite-side thereof, said pilot valveibeinglalso connected to be oppositely moved bythe high pressure received from the valve, and means "to insure full movement of the pilot valve beforelthe directional valve reaches the end of its movement.

14. In a reversing mechanism for use with a highfiuid-pressure line and a low fluid pressure line, a first and a second port ad-apted:tobe.re spectively connected to the high and the .-low pressure lines, and vice versa, a directional valve movable to opposite positions to determine which of the conneotionsshall be afluidpressureoperated pilot'valve-movable toiopposite positions for'controlling movement of-the direction-a1 valve, there being oppositepressure chambersforthe pilot'valve, 'meansresponsive to pressure in the outlet connected with high pressure, oppositely to connect the pressure chambers of the pilot valve to the high and low pressure ports, respectively, and vice versa, to effectmovement of the pilot valve to reverse the position of the directional valve upon attainmentiof a predetermined pressure in the high pressure outlet, andimeans regulating flow of fluid to both pressure chambers of the pilot valve to insure full movement -.of the moved to relieve the connection of the high pressure line on the outlet initiallyconnected-therewith.

15. In a mechanism of the kind described, a 'pressure'control having a fluid-pressureinl'et and an exhaust, apair of fiuid pres'sureiports, and means selectively tolconnect" one port to theinlet and the other to exhaust, "and 'vice -versa,'said means comprising a first valve displ'aceable to effect said connections selectively, and opposite pressure means adapted selectively for connection to fluid pressure or exhaust 'for displacement of said first valve, a second valve for controll ing said opposite pressure means of said first valve,-:

the second valve "being displaceable to "connect selectively one side (if said means to pressure and '-the other to eiihaust, and vice versa, means restricting the "fluid-flow around said second valve to both of said opposite pressure means'o'fthe "-firs't valve to delay movement of the' latten'opposite 'flu id-pressure'means adapted selectively vforr "connection to -fiu id pressure or exhaust for:di's

placement of the second valve, fluid pressurere'sponsive means to connect the opposite pressure means of the second valve topres'sure and/exhaust, respectively, and to reverse said connec- "tions, said connections 'for'operation o'i the second -valve being relatively unrestricted to insure full *operation'thereof at'least by the time thefirst valve'h-as'been moved.

16. In a mechanism of the kind described, :a pressure control hav'ing a fluid-pressure inletand *an "exhaust, a -'pair of fluid-pressure ports, and means selectivly'toconnect one port to the" inlet and the other to exhaust, and vice versa, said means comprising a first valve displaceableto effect said connections selectively, and "opposite pressuremeans adapted selectively for connection to fiu id pressure or eiihaustfor displacement'of said 'firstvalve, a second valve for controlling said opposite -'pressure meahs oi said valve, the second valveibeing displaceable to :connectselectively one s'ideof saidmeans to pressure and" the other to exhaust, and viceversa, means restricting the fluid 'flow around said second valve to each of said opposite -pressure"means ofthefirstvalve to delay'movement of thelatter, opposite fluidpressure means adapted selectively for "connection to fluid pressure or ex'hausfifor displacement "of the second valve, fluid "pressure-responsive means connected to said fluid-pressure ports whereby to operate when thefiuid pressure inthe port connected with high pressure attains a predetermined-value, and passage means valved 'by the fluid pressure respon'sive means 'for "selectivelyconnecting one of the opposite pressure *means'o'f the second valveto high-pressure and the other to low pressure, and vice versa,-whereby the second valve will-be moved upon attainment of thepredetermined pressure in the high pressure port, and means-to prevent movementof the the second valvehas beenm'oved.

1'7. A'reversing valve mechanism including '"a housing, a high pressure inlet, a low pressure outlet, a pair of work outlets leading from the housing, locking'valve means normally urged to close said Work outlets, pressure means connected with the high-pressure inlet to open the "valve when high pressure exists in theinlet, a directional valve in the housing movable to'selectively connect one work line with the inlet and the other with rthe outlet, and vice versa, relief valve means in the housing,,pressureeresponsive means oppositely connecting the relief valve means with the-work lines so that the. relief ivalve means .is moved inrespOnse-to .pressureconditions in the work lines, and 'means the housing, responsive to movement-of the relief valve means, to move the "directional valve .to reverse the=con- :nections'of the inlet andout-let with the work rlines, the connection of the pressure means of fthez'locking valvemeans and the inlet' fbeing inde pendent "of "said" directional valve andireli'ef'valve (means.

18. A :reversing valve mechanism including a housing, a high'pressure inlet and allow pressure from the housing, a pressure-operated-relief valve having opposite pressure chambers connected respectively to the two work lines, spring means normally urging the relief valve to intermediate position, the relief valve having a high pressure passage flanked by two low pressure passages separated from the high pressure passage, the high pressure passage being connected with the high pressure inlet, a directional valve in the housing having two separated passages thereon, the directional valve being connected with the highpressure inlet and the two Work lines, a pair of exhaust passages connected with the directional valve, arranged so that the directional valve can move to connect the high pressure inlet to either work line through one of its passages and to connect the other work line to the exhaust passage through the other passage, and vice versa,

opposite pressure chambers for operation of the directional valve, means for connecting said chambers to the high and low pressure lines, said .means including fluid lines controlled by the relief valve, said relief valve in intermediate position being adapted to close said lines, and when moved in one direction from intermediate position, disposing its high pressure passage to connect one fluid line to the high pressure line and disposing One of its flanking passages to connect the other fluid line to the low pressure outlet, and when moved in the other direction from intermediate position, said relief valve making opposite connections for said fluid lines.

19. A reversing valve mechanism including a housing, a high pressure inlet and a low pressure outlet thereinto, a pair of work lines connected from the housing, a pressure-operated relief valve having opposite pressure chambers connected respectively to the two work lines, spring means normally urging the relief valve to intermediate position, the relief valve having a high pressure passage flanked by two low pressure passages separated from the high pressure passage, the high pressure passage being connected with the high pressure inlet, a directional valve in the housing having two separated passages thereon, the

directional valve being connected with the high pressure inlet and the two work lines, a pair of exhaust passages connected with the directional valve, arranged so that the directional valve can move to connect the high pressure inlet to either I work line through one of its passages and to connect the other work line to the exhaust passage through the other passage, and vice versa, opposite pressure chambers ior operation of the directional valve, means for connecting said chambers to the high and low pressure lines, said means including fluid lines controlled by the relief valve, said relief valve in intermediate position being adapted to close said lines, and when moved in one direction from intermediate position, disposing its high pressure passage to connect one fluid line to the high pressure line and disposing one of its flanking passages to connect the other fluid line to the low pressure outlet, and when moved in the other direction from intermediate position, said relief valve making opposite connections for said fluid lines, and said means for connecting said chambers of the directional valve including also a pressure-operated pilot valve having opposite chambers connected to said fluid lines of the relief valve for the pilot valve to be operated in response to the aforesaid movement of the relief valve, said pilot Valve having two separated valving passages, and having connections to the high pressure inlet and to the exhaust, and having fluid lines to the opposite chambers of the directional valve, said pilot valve being movable from a position to connect the high pressure inlet to one chamber of the directional valve, and the exhaust to the other chamber of said directional valve, and vice versa.

20. A reversing valve mechanism including a housing, a high pressure inlet and a low pressure outlet thereinto, a pair of work lines connected from the housing, a pressure-operated relief valve having opposite pressure chambers conneoted respectively to the two work lines, spring means normally urging the relief valve to intermediate position, the relief valve having a high pressure passage flanked by two low pressure passages, separated from the high pressure passage, the high pressure passage being connected with the high pressure inlet, a directional valve in the housing having two separated passages thereon, the directional valve being connected with the high pressure inlet and the two Work lines, a pair of exhaust passages connected with the directional valve, arranged so that the directional valve can move to connect the high pressure inlet to either work line through one of its passages and to connect the other work line to the exhaust passage through the other passage, and vice versa, opposite pressure chambers for operation of the directional valve, means for connecting said chambers to the high and low pressure lines, said means including fluid lines controlled by the relief valve, said relief valve in intermediate position beng adapted to close said lines, and when moved in one direction from intermediate position, disposing its high pressure passage to connect one fluid line to the high pressure line and disposing one of its flanking passages to connect the other fluid line to the low pressure outlet, and when moved in the other direction from intermediate position, said relief valve making opposite connections for said fluid lines, and fluid pressure-operated locking valve means having fluid chamber means connected with the high pressure inlet, said locking valve means being movable by pressure in said inlet to open position, and means to move said locking valve means to closed position in absence of pressure in said inlet, sald locking valve means being disposed in said work lines to open them when the locking valve means is open.

HOWARD E. ROSE.

REFERENCES CITED The following references are of record in the file of this patent:

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